<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>计算器</title>
    <link rel="stylesheet" href="./css/index.css">
</head>
<body>
    <div id="app">
        <!-- 计算器 -->
        <div class="input-num">
            <button @click="sub">
                -
            </button>
            <span>{{num}}</span>
            <button @click="add">
                +
            </button>
        </div>
        <img src="http://www.itheima.com/images/logo.png" alt="">
    </div>
    <!-- 开发环境版本，包含了有帮助的命令行警告 -->
<script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
<script>
    // 创建vue实例
    var app=new Vue({
        el:"#app",
        data:{
            num:1,
        },
        methods:{
            
            add(){
                if(this.num<10){
                    this.num++;
                }else{
                    alert("别点了，最大了")
                }
            },
            sub(){
                if(this.num>0){
                    this.num--;
                }else{
                    alert("别点了，最小了");
                }
            }
        },
    });
</script>
</body>
</html>
